CA1075075A - Stabilized fodder preserving solution containing formaldehyde - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
The present invention provides a stabilized fodder preserving solution containing formaldehyde and besides formalde-hyde organic acid, preferably formic acid and/or inorganic acid, preferably sulphuric, hydrochloric or phosphoric acid, and urea as a stabilizer, characterized in that the volume ratio of the 36 to 40% formalin and the acid used falls within the range 1:1.2.to 1:2.5, the solution containing 8.5 to 13.5 acid equiv-alents per litre of solution.

Description

The present invention relates to a stabilized fodder preserving solution containing formaldehyde.
It is well known that formalin combined with other sub-stances can be used as a fodder preserving agent. The diminish-ing effect of formalin on the conservation losses and the improv-ing effect on the nutrient utilization are also well-known. The problems have been the polymerization of formaldehyde in solutions, although formalin often contains for instance methanol as a poly-merization inhibitor, and also the low flash point, particularly in solutions where inorganic acids have been used, such as sul-phuric acid, hydrochloric acid,-phosphoric acid.
A known and also experimentally tested method is to mix formalin and acid each from separate vessels at an individually adjusted ratio only at the preparation stage of the preserved fodder directly into the fodder by means of a separate mixing device.
However, this has not proved to be a usable method in practice primarily because of the polymerization of the formalin and the difficult handling of the strong acids. Furthermore, formalin and acid used together in the same solution give a better result than each substance used separately.
The amounts of acid in the present preserving solutions containing formalin have gener~lly been rather small, only about :

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1~75075 3 to 5 acid equivalents per liter.
In order to ensure a better conserving effect it would be appropriate if the amount of acid could be increased, in which case the pH of the fodder would be more certain to decrease.
According to recent investigations a comparatively strong pH
decrease together with the conserving effect of formalin gives, so far as a fodder preserving solution is concerned, the best possible result. If the acid used is for instance hydrochloric or sulphuric acid, an increase in the amount of the acid has further the advan-tage that the cost of the product will decrease correspondingly.
Furthermore, the present fodder preserving formalin containing solutions contain predominantly formalin, e.g. in the ratio of 1 part of acid to 2 parts of formalin (so called Viher-solution (Farmos Oy)), which is described in the Finnish patent no. 43941, and Sylade (Imperial Chemical Industries), which is described in the Finnish patent application no. 3276/72, according to which even 9 parts of volume of formalin to one part of volume of acid may be used.
Unexpectedly it has now been found that the proportion of formalin in the preserving solution may be substantially decreased without the advantageous conserving effect of formaldehyde diminish-ing~ as far as the fodder quality and the conserving of nutrients are concerned.
At the same time laboratory experiments have surprisingly shown that the preserving solutions containing formalin can be made to stay clear if the ratio of formalin and acid is kept within compa-ratively narrow limits which limits also in preservation experiments have proved considerably more advantageous than those prior used.
The invention concerns stabilized fodder preserving solutions containing formaldehyde, the characteristics of which appear from the appended claims. The stabilized solutions comprise formalin ~-and inorganic or organic acid~ whereby as inorganic acids pre-ferably hydrochloric, sulphuric and/or phosphoric acid and as or-ganic acid preferably formic acid, or their mixtures, come into question. The limits within which the preserving solution has both a good conserving and stabilizing effect is formalin : acid =
1 : 1.2 to 1 : 2.5 by volume whereby the solution contains 8.5 to 13.5 equivalents of acid per liter solution.

- 2 -By formalin is meant a 35 to 40 % aqueous formaldehyde solu-tion containing methanol and to which is further added e.g. carboxy methyl cellulose~ hydroxy ethyl cellulose, vinyl acetate telomer, or some other known formaldehyde stabilizer.
Irrespective of the stabilizing agent initially added to the formalin~ about 1 to 2 per cent by weight of urea is added to the preserving solution according to the invention, preferably dissolved in water before mixing.
By stabilization is meant that the solution stays clear within a wide temperature range (from room temperature to -20C~ the flash point at the same time staying sufficiently high.
According to the statute no. 335/54 concerning flam~able liquids, a liquid the flash point of which is below 55C is considered to belong to the group of flammable liquids. By means of the stabilized composition according to the invention not only is the polymerization prevented but also a sufficiently high flash point is ensured.
To the above mentioned stabilization problem chemists have for years tried to find a simple, economical, and practical solution, however, without any success. With the preserving solution according to the present application it has been possible to solve these prob- -le~s in a way that is rather surprising even to those highly skilled in the art.
The following examples and tables illustrate the invention as to the stabilization of the solutions. The percentages imply per cent by weight if not otherwise indicated.
Example 1 - 27.9 parts by vol. of formalin, which contains 37% formaldehyde and 4.8 % methanol, - lO - " - stabilizer containing 17% urea and 83%
water 46.8 - " - sulphuric acid, 80 %, and - " - water are mixed. 100 parts by volume of a solution is obtained, the flash point of which is above 70C and which keeps at least one month at -20C without forming a precipitate.
Example 2 31.0 parts by vol. of formalin, flash point 68C containing q 37 % formaldehyde and 8.9 % methanol, 10.0 - " - stabilizer containing 17 % urea and 83 %
water,

- 3 -' ' ' 37.4 parts by vol. of sulphuric acid, 80 %, and 26.1 - " - water are mixed. 100 parts by volume of a solution is obtained, the flash point of which is 70C and which keeps at least one month at -20C without forming a precipitate.
Example 3 31 parts by vol. of formalin, flash point 68C containing 37 %
formaldehyde and 8.9 % methanol, 10 - l' - stabilizer containing 17 % urea and 83 %
water, 42.1 - " - sulphuric acid, 80 %, and 20.9 - ~ - water are mixed. 100 parts by volume of a solution is obtained the flash point of which is 70C and which keeps at least one month at -20C
without forming a precipitate.
Example 4 18.6 parts by vol. of formalin containing 37 % formaldehyde and 4.5 % methanol, 46.8 - " - sulphuric acid, 80 %, ~ " - stabilizer containing 17 % urea and 83 %
water~ and 29.5 ~ " - water are mixed. 100 parts by volume of a solution is obtained the flash point of which is above 70C and which keeps at least one month at -20C without forming a precipitate.
Because concentrated, 80%, sulphuric acid is used in the examples, the volume of the obtained solution does not correspond to the sum of the amounts of the different substances.
Example 5 31.0 parts by vol. of formalin containing 40 % formaldehyde, 37.8 - " - phosphoric acid, 85%, 10.0 , " - stabilizer, and 21.2 - ~' - water are mixed. The flash point of the solution obtained is above 70C
and it keeps at -20C without forming a precipitate.
.

- 4 -iO75075 Example 6 21.4 parts by vol. of formalin containing 35.2 % for~aldehyde and 6.3 % methanol, 60.0 - " - hydrochloric acid, 37%, 10.0 - " - stabilizer~ and 9.6 - " - water are mixed. A clear solution is obtained the flash point of which after storing for 10 months is 65C and which keeps at -20C 10 months without precipitating.
The water content may also be substituted with acid.
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10~75075 From tables I and II can be seen that the solutions stay clear for a long time within very narrow limits, according to table I (where the formalin contains 8.9 % methanol), the ratio of formalin : acid being 1 : 1.2 to 1 : 1.5 (b,c,d) and according to table II (where the formalin contains only 4.8 % methanol) within the limits formalin : acid 1 : 1.68 to l : 2.5 (2,3,4,5). The diffe-rence is obviously due to the different methanol concentrations.
Within these limits the solutions have stayed clear for one month at room temperature to -20C and the flash point has been 67C to ~70C
According to our experience a solution which stays clear for one month will continue to stay unchanged.
Performed conserving tests have given extremely good results.
These results are given in the following examples.

Test 1 Composition of the Formic Test Viher- Press test solutions acid solution solution fodder (80 %) Formalin vol.% 35 55 N2SO4 (80%) vol.% 44 Acetic acid -"- - 24 Water -"- 21 21 Contents of effluent juice:
Dry matter (Z) 5.69 5.19 5.16 5.72 Protein (%) 1.66 1.35 1.31 1.80 Quality of silage:
pH 3.8 4.1 4.2 4.2 Raw protein (in dry matter) 22.1 22.4 22.1 20.7 Digestible raw protein g/fodder unit 183 192 190 181 In all experiments the preserving solution has been used at an amount of 5 1/1000 ~g fodder.

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Thus it can be seen that in test solution 1 less dry matter and protein escape from the silo together with the efflu-ent juice than is the case with fodder preserved with formic acid.
On the other hand the corresponding values are more or less the same both for the Viher-solution and the test solution 1, although test solution 1 contained considerably less formalin than the Viher-solution.
The following test concerned the amounts of CO2 formed, which formation indicates impure fermentation in the fodder mass.
Test 2 -Formic Test Viher-acid solution solution (80~) Amount of CO2 g/1000 kg of 289 0 37 fodder Test solution 1 gave also in this respect a better re-sult than the other. The evolution of gas from the press fodder was so great that it was not possible to collect it all.
Test 3 - 20 Composition of Formic Test Test Press test solution acid solution solution fodder (80%) 2 3 I Formalin vol. % 26 26 - H2SO4 (80%) vol. % 31 47 Water 43 27 Quality of fodder: -pH 4.39 4.17 3.94 4.84 Lactic acid (%) 0.48 1.23 0.95 1.14 Acetic acid (%) 0.21 0.47 0.29 0.74 ; Propionic acid (%) 0.09 0.06 0.06 0.10 Soluble N % of tot.N 50.4 46.2 39.9 57.7 --Content of protein in effluent juice % 1.48 1.36 1.34 1.64 .. ''' ' ' :~07S075 The amount of preserving solution used in all tests is 5 1/1000 kg of fodder.
The amount of preserving solution per 1000 kg, used in the preceding examples, may of course vary to some extent, depend-ing on the quality of the fodder as well as Oh other conditions.
A suitable amount is generally 4-6 1/1000 kg fodder. -From the results is seen that the acid addition has a pH lowering effect. In the test/preserving solution was used to give an acid amount per 1000 kg fodder as follows:
Formic acid 80 equiv.
Test solution 2 44 "
Test solution 3 66 "
More effective than the acid addi'ion is, however, the combined effect of formalin and acid when used at the above ratios.
The formation of the desired acids has been most effec-tive in a preserving solution having a formalin : acid ratio of 1 : 1.2 (test solution 2). Even stronger has been the formation of acid in press fodder, but its pH has not however decreased to the desired level.
Test 4 Composition of the Test Test Test Formic test solutions: Solution Solution Solution acid (80%) -Hydrochloric acid 35% 72 vol% 39 vol%14 vol%

Formalin 2B " 61 " 86 "

Formalin:Hydro-chloric acid 1:2.57 1:0.64 1:0.16 ; added amount 1/1000 kg 6.0 5.7 8.1 4.0 Acid equiv./1000 kg ' fodder 49.5 26.0 13.0 90.0 ; 30 Conserving results pH 4.45 4.75 4.92 4.41 Lactic acid (%) 0.88 0.76 0.54 0.61 Soluble N/tot.N (%) 33.5 29.0 25.6 46.6 (Test 4 cont) Conserving losses:
Dry matter (%) 0.2 3.3 6.1 5.2 Ash (%) 5.5 15.5 18.9 7.2 Raw protein (%) 1.7 2.7 8.8 6.5 Fibres (%) 7.6 16.8 15.2 10.4 Palatableness for sheep:
g dry matter/day/sheep 1035 1068 772 1007 The test resuLts show that the best conserving results were obtained with a combination, in which the ratio of formalin to hydrochloric acid was about 1:2.5. With this combination the same pH-level in fodder was reached as by using formic acid, the acid effect of which is about twice to that of test solution 4.
When formalin and acid are used in the above ratio, the sub- - -stances increase the effect of each other. In this way a good conserving effect is obtained with only small losses.

Test 5 - -Composition of Test Viher- Press test solutions solution solution fodder Formalin vol% 21 55 H2S04 (80%) 47 _-Acetic acid 24 Quality of fodder:
pH 4.2 5.1 5.3 NH4-N (%) 0.024 0.028 0.071 Pure protein (%) 2.7 2.8 1.5 Sugar (%) 0.6 1.6 0.2 Lactic acid (%) 3.0 2.1 1.5 Palatableness:
kg/beef cattle/day 26.5 25.2 21.5 Digestible raw protein g/fodder unit 202 211 178 , Test solution 7 has brought forth a strong formation of lactic acid~ which together with the added acid has remarkably decreased the pH. The smaller amount of acid and the greater amount of formalin in the Viher-solution have slowed down the lactic acid fermentation. The smaller amount of formalin inttest solution 7 has been sufficient to protect the fodder against protein losses.

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Table IV
Palatableness: Press Viher-solution Viher-acidX) Propionic +
fodder (acc.to Finnish sulphuric acid pat.43941) kg/animal/day 18.2 19.7 21.0 18.6 growth increase kg 69.3 84.6 102.0 83.5 -"- g/day 598 730 879 720 Viher-acid contains:
Sulphuric acid H2S04 42.0 /O
Formalin , 40 % HCH0 25.0 %
Urea (NH2)2C0 1.7 %
Water H20 31.3 %

It has thus been proved that the preserving solutions meet the extremely high demands of stabilization and fodder conservation.

_ 14 -

Claims (11)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A stabilized fodder preserving solution containing formaldehyde, an acid and urea as a stabilizer, the volume ratio of the 36 to 40% formalin and the acid being in the range 1:1.2 to 1:2.5 and the solution containing 8.5 to 13.5 acid equival-ents per liter of solution.

2. A solution as claimed in claim 1 in which the acid is an inorganic acid.

3. A solution as claimed in claim 1 in which the acid is an organic acid.

4. A solution as claimed in claim 2 in which the inorganic acid issulphuric,hydrochloric or phosphoric acid.

5. A solution as claimed in claim 3 in which the organic acid is formic acid.

6. A solution according to claim 1, 2 or 3 in which the formalin in the solution contains methanol.

7. A solution according to claim 1, in which the acid is 80% sulphuric acid.

8. A solution according to claim 1 in which the acid is 35% hydrochloric acid.

9. A solution according to claim 1 in which the acid is 80% formic acid or a corresponding amount of acetic acid.

10. A solution according to claim 1, in which the acid is 85% phosphoric acid which in the preserving conditions has been considered as a dibasic acid.

11. A solution according to claim 1, 2 or 3, which contains about 10 vol. % of a urea solution of about 17 weight-%.